Blasting cartridge



Feb. 16, 1932. s. TEs 1,845,687

I BLASTING CARTRIDGE Filed June 9, 1931 11v VENTOR Patented Feb. 16, 1932 STEPHEN TESE, OF ROCHESTER, NEW YORK BLASTING CARTRIDGE Application filed June 9, 1931'. Serial No. 543,189.

My present invention relates to explosives and more particularly to prepared explosive charges, such as are used in blasting, and it has for its object to provide an improved blasting cartridge of simple construction that may be manufactured at low cost and handled with the greatest safety. The improvements are directed in part toward structure facilitating loading the explosive charge itself in the cartridge, toward the manner in which it is supported therein, and toward arrangements for electrically detonating the charge.

To these and other ends, the invention resides in certain improvements and combinations of parts, all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawings:

Fig. 1 is a central longitudinal section through a cartridge constructed in accordance with and illustrating one embodiment of my invention;

Fig. 2 is a transverse section on the line 2-2 of Fig. 1; and

Fig. 3 is a transverse section on the line 83 of Fig. 1.

Similar reference numerals throughout the several views indicate the same parts.

While features of my invention are applicable to the construction of blasting and similar cartridges, whatever the explosive agent may be, including dynamite and nitroglycerine, even these may be employed with respect to some aspects of my invention, but, in general, my purpose is to provide a substitute therefor which, with less care, may be safely handled in their place. In the .use of dynamite, for example, it has been customary to prepare the explosive charge in the immediate region of the blasting operation.

The preparations aften involve drilling a hole in the rock or other formation to be dislodged, filling the hole with the explosive in connection with a detonator, and tamping down the charge. This must be done with great care and particularly when nitro-glycerine is used instead of dynamite, a scratch on the unit or a spark generated by abrasive contacts will prematurely set off the charge.

In the practice of my invention,I preferably use a less sensitive and less dangerous explosive element, but in any case, I so combine it in a prepared shell or cartridge that the usual hazards attendant upon manipulation and placing are obviated.

Referring more particularly to the drawings, my improved cartridge in the embodiment shown embraces a metallic shell 1, preferably in the form of a cylinder, closed at its bottom 2 and having a-threaded neck 3 of substantial extent, upon whichis screwed a relatively long cap 4. This shell and cap are preferably of zinc toprovide a hermetically sealed container. Such'containeris provided throughout with an asbestos lining 5 and when assembled is covered by an outer asbestos jacket 6. The contents of the screwcapped shell are assembled within the lining 5 in the following order: At the base is a body of ordinary bran or similar fiocculent dry material 7 upon which is deposited the main body of the explosive 8, which is preferably composed of a mixture of chlorate of potassium, black antimony and bronze aluminum powder. This is sealed'at the top by a layer or body 9 of pipe clay, chalk, infusorial earth or similar plugging material. Above that and between it and the cap 1 is another body of bran 10. As the screw cap 4 is turned down into place, it holds all of these elements together and compresses the bran to a certain eXtent while at the same time leaving it as a soft cushion.

Such a structure supports the explosive body between two cushioning devices that reduce shock due to dropping or tamping, while at the same time hermetically sealing it in a body that is highly insulated against the com munication of heat thereto.

While the detonation may be produced through the incorporation of ordinary fuses with or without blasting caps in the place of circuit wires, I prefer to accomplish this by means of a resistance wire or coil 11 imbedded in the center of the explosive body 8 and which, upon being charged with the usual high voltage used in such cases, becomes incandescent or heats to a temperature sufficient to destroy the equilibrium of the explosive components and produce the explosion. For instance, a fine banjo string may be used. It is connected to the terminals 12 and 13 that pass out through the top of the cartridge, as shown, with proper sealing and are connected up with an electric flash system of high Voltage, including the wires 14, 15 and 16 in a circuit from a battery 17, including an operating switch 18, all of which last described parts are diagrammatically shown in Fig. 1. The practice with respect to effecting electrical detonation.

in explosives in this manner is so well known that further explanation is unnecessary.

The particular explosive mixture that I have specified herein and which I prefer to use lends itself peculiarlyto detonation by electrical means because of its metallic character and its resultant rapid heat absorption. This taken together with the central location of the resistance wire 11 promotes instantaneous explosion.

I claim as my invention: 1. A blasting cartridge embodying in combination, a metallic container having a threaded neck, a threaded cap therefor, a body of explosive within the container, a cushioning body on the bottom of the container between it and the explosive body, and another cushioning body above the explosive beneath the cap, said cushioning bodies being composed of bran.

2. A blasting cartridge consisting of a metallic shell 'open at one end and closed at its opposite end, a metallic cap closing the open end of the shell and connected thereto by a long screwthread, cushioning means within the cap and closed end of the shell, an explosive confined within the shell and cap between the cushioning means, a seal of earthy material between the cap cushion and the adjacent end of the explosive, asbestos completely lining and covering the, shell and cap, a resistance in the center of the explosive, andconducting wires'lea'ding from said resistance to the exterior of the shell.

STEPHEN TEsE. 

